The present invention relates to an ear tag for marking an animal, according to the preamble of claim 1.
Such an ear tag is known, for example from GB-A-1 293 157. These and other ear tags fitted in the same way are put on the market in large numbers for quick and simple marking of, for example, pigs and cows. When the tag is fitted, the pin projects through the ear of the animal, and a part of the ear tag which is generally plate-shaped is situated on both sides of the ear. For the visual identification of the animal one part or both parts can be provided with identification marks. The parts of the ear tags are manufactured as far as possible from plastic material, in order to permit mass production at low cost. It is pointed out that the invention also relates to ear tags in which the pin and the first part are manufactured integrally.
The ear tag disclosed in GB-1 293 157 has a plastic pin comprising a shank with a pointed head, in which the pointed head is pyramid shaped. The sharp edges of the pyramid provide for a concentration of the pressing-in force, thereby facilitating the penetration through the ear of the animal. This concentration of the pressing-in force is however insufficient to obtain a noticeable improvement when the pin penetrates through the ear of the animal.
Another ear tag is described in EP 0,105,796 and has a hollow pin made of flexible plastic. The conical head of the pin is provided with a very hard element, particularly of metal, which forms the pointed part of the head. The object of providing this very hard point is to achieve improved penetration of the pin into the ear of the animal. This is advantageous both for the animal and in terms of the force required for fitting the tag. The fact that the shank of the pin is made of a flexible material, in such a way that the shank can withstand the pressure load occurring during the insertion, has the generally accepted advantage that it gives the first and the second part of the ear tag a certain mobility. This is important, for example, if the animal becomes caught up somewhere by ear tag. Moreover, in a design of the ear tag in which the pin is integral with the first part, on account of the desired flexible material of the first part, making the pin of the same flexible material is a great advantage as far as production is concerned.